tcp: use hash_32() in tcp_metrics

Fix a missing roundup_pow_of_two(), since tcpmhash_entries is not
guaranteed to be a power of two.

Uses hash_32() instead of custom hash.

tcpmhash_entries should be an unsigned int.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 15 deletions

diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c
index 99779ae44f64..992f1bff4fc6 100644
--- a/net/ipv4/tcp_metrics.c
+++ b/net/ipv4/tcp_metrics.c
@@ -7,6 +7,7 @@
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/tcp.h>
+#include <linux/hash.h>
 
 #include <net/inet_connection_sock.h>
 #include <net/net_namespace.h>
@@ -228,10 +229,8 @@ static struct tcp_metrics_block *__tcp_get_metrics_req(struct request_sock *req,
                 return NULL;
         }
 
-        hash ^= (hash >> 24) ^ (hash >> 16) ^ (hash >> 8);
-
         net = dev_net(dst->dev);
-        hash &= net->ipv4.tcp_metrics_hash_mask;
+        hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
 
         for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
              tm = rcu_dereference(tm->tcpm_next)) {
@@ -265,10 +264,8 @@ static struct tcp_metrics_block *__tcp_get_metrics_tw(struct inet_timewait_sock
                 return NULL;
         }
 
-        hash ^= (hash >> 24) ^ (hash >> 16) ^ (hash >> 8);
-
         net = twsk_net(tw);
-        hash &= net->ipv4.tcp_metrics_hash_mask;
+        hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
 
         for (tm = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain); tm;
              tm = rcu_dereference(tm->tcpm_next)) {
@@ -302,10 +299,8 @@ static struct tcp_metrics_block *tcp_get_metrics(struct sock *sk,
                 return NULL;
         }
 
-        hash ^= (hash >> 24) ^ (hash >> 16) ^ (hash >> 8);
-
         net = dev_net(dst->dev);
-        hash &= net->ipv4.tcp_metrics_hash_mask;
+        hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
 
         tm = __tcp_get_metrics(&addr, net, hash);
         reclaim = false;
@@ -694,7 +689,7 @@ void tcp_fastopen_cache_set(struct sock *sk, u16 mss,
         rcu_read_unlock();
 }
 
-static unsigned long tcpmhash_entries;
+static unsigned int tcpmhash_entries;
 static int __init set_tcpmhash_entries(char *str)
 {
         ssize_t ret;
@@ -702,7 +697,7 @@ static int __init set_tcpmhash_entries(char *str)
         if (!str)
                 return 0;
 
-        ret = kstrtoul(str, 0, &tcpmhash_entries);
+        ret = kstrtouint(str, 0, &tcpmhash_entries);
         if (ret)
                 return 0;
 
@@ -712,7 +707,8 @@ __setup("tcpmhash_entries=", set_tcpmhash_entries);
 
 static int __net_init tcp_net_metrics_init(struct net *net)
 {
-        int slots, size;
+        size_t size;
+        unsigned int slots;
 
         slots = tcpmhash_entries;
         if (!slots) {
@@ -722,14 +718,13 @@ static int __net_init tcp_net_metrics_init(struct net *net)
                         slots = 8 * 1024;
         }
 
-        size = slots * sizeof(struct tcpm_hash_bucket);
+        net->ipv4.tcp_metrics_hash_log = order_base_2(slots);
+        size = sizeof(struct tcpm_hash_bucket) << net->ipv4.tcp_metrics_hash_log;
 
         net->ipv4.tcp_metrics_hash = kzalloc(size, GFP_KERNEL);
         if (!net->ipv4.tcp_metrics_hash)
                 return -ENOMEM;
 
-        net->ipv4.tcp_metrics_hash_mask = (slots - 1);
-
         return 0;
 }